Cashew as a marketable commodity, has a very important role to
play in the liberalized Indian economy. With export earnings of Rs. 12,320
million in 1995-96, cashew ranked as one of the top agricultural export
commodities. From the farmers as well as from the exporters point of
view, the current emphasis that cashew is receiving as a horticultural crop from
the research and development front, is a welcome sign. At present, India has a
processing capacity of nearly seven hundred thousand metric tons and to meet the
raw nut demand, the country depends partially on imports from several African,
and in recent years, from south-east Asian countries. This has considerable
drain on the countrys foreign exchange reserves and there is an urgent
need to increase local production to substitute imported raw material in order
to derive the maximum benefits from a strong processing and marketing capability
developed over the years by the Indian cashew industry.

Research work on cashew was initiated on a relatively small
scale in early 1950s resulting in the development of several production
techniques. These efforts were further strengthened when the national research
mandate was delegated to the Central plantation Crops Research Institute
(CPCRI), Kasaragod, in 1970 which spearheaded the All India Coordinated Spices
and Cashew improvement Project from 1971. These research activities received
further impetus with the implementation of a World Bank aided multi-State Cashew
Project in the States of Andhra Pradesh, Kerala, Karnataka and Orissa from
1982-86. A National Research Center for Cashew was established at Puttur to
increase the production and productivity of cashew with the mission-mode
approach in 1986.

The cashew development component of the combined All India
Coordinated Spices and Cashew Improvement Project was de-linked and an
independent National Cashew Research project was initiated with the newly
established National Research Center (NRC) for the crop at the same time. There
are 8 research centers and one sub-center at present, located in 8 cashew
growing States in the country. This can be considered as a milestone in cashew
development with firmly established linkages with the Directorate of Cashew nut
Development Corporation and other extension agencies which assisted in the
transfer of newly developed production technologies.

2. PRESENT STATUS OF CASHEW PRODUCTION

2.1 Areas of Production

Cashew is grown in the western and eastern coastal areas and
further inland in some parts of Karnataka and Madhya Pradesh. Currently, the
area under cashew is around 634,900 ha with a total production of 417,000 tons
(Table 1). With 118,000 ha and a production of 140,000 tons, Kerala accounts for
18.6 % of the area and 33.5 % of production respectively. The highest
productivity is observed in Kerala and Maharashtra with over one ton per ha. The
high yields in Maharashtra are primarily due to the fact that cashew production
is of recent origin and the major part of the plantations have been established
with high yielding clonal material. Even the orchards raised from seeds are from
selected progenies. The current targets are set to produce 700,000 tons from
700,000 ha by the year 2000 AD.

Table 1. Area, Production and Productivity of Cashew in
India (1965-96)

States

Area (ha)

National % Area

Production (tons)

National % Prod.

Productivity (kg/ha)

Kerala

118,600

18.6

140,000

33.5

1,180

Karnataka

83,900

13.2

37,600

8.9

448

Goa

49,600

7.8

17,800

4.3

359

Maharashtra

66,700

10.5

69,000

16.5

1,034

Tamil Nadu

77,360

12.2

30,930

7.4

400

Andhra Pradesh

118,080

18.6

71,700

17.2

607

Orissa

101,850

16.0

43,000

10.3

422

West Bengal

8,680

1.4

6,960

1.7

802

Others

10,200

1.6

840

0.2

82

Total

634,970

100.0

417,830

100.0

658

2.2 Varieties

Thirty-threecultivars have been released so far by the
National Research Center as well as several Agricultural Universities. Most of
the varieties have a mean yield of 8-10 kg per tree which gives over one ton per
ha. In view of the export potential however, cultivation is recommended only for
such cultivars that have a kernel grade of W-210 to W-240 (210-240 kernels per
lb). Cashew cultivar recommendations for different States are given in Table
2.

3. PROPAGATION AND PRODUCTION OF PLANTING
MATERIAL

A number of propagation methods have been tested for the
multiplication of cashew. Air-layering was found to be one of the popular
methods among growers. This technique however, produced trees with poor
anchorage as the root density was found to be low. It also resulted in poor
field establishment and high susceptibility to cyclones and drought conditions.
Air layering was therefore found to be unsuitable for commercial exploitation.
In the case of mound layering too, the absence of a tap root was found to be a
disadvantage. Epicotyl grafting was another method that had limitations due to
high mortality at transplanting and incidence of collar-rot at the nursery
stage. Soft-wood grafting developed at the research centers was found to be the
most viable method of propagation that was commercially acceptable; it gave a
success rate of about 70 percent. The technique of soft-wood grafting described
below is similar to epicotyl grafting except the difference in the age of the
rootstock.

Table 2. Cashew Cultivars Recommended for Different States
of India

State

Cultivars Recommended

Progeny

Karnataka

Selection 1

VTH-107/3

Selection 2

VTH-40/1

Ullal 1

8/46 Taliparamba

Ullal 2

3/67 Guntur

Ullal 3

5/37 Manjeri

Ullal 4

2/77 Tuni: Andhra

UN 50

2/27 Nileshwar

VRI 1

M-10/4

VRI 2

M-44/3

Vengurla 1

Ansur-1

Vengurla 4

Mid Red x Vetore 56

Chintamani 1

8/46 Taliparamba

Kerala

Madakkathara 1

BLA-39-4

Madakkathara 2

NDR 2-1

K-22-1

22 Kottarakkara

Dhana

ALGD-1-1 x K 30-1

Priyanka

BLA-139-1 x K 30-1

Maharashtra and Goa

Vengurla-1

Ansur-1

Vengurla-4

Mid Red x Vetore-56

Vengurla-6

Vetore 56 x Ansur-1

Tamil Nadu

VRI-1

M 10/4

VRI-2

M 44/3

VRI-3

M 26/2

Andhra Pradesh

BPP-4

EPM 9/8

BPP-6

T No.56

BPP-8

T No.1 x T No. 39

VRI-2

M 44/3

Orissa

VRI-2

M 44/3

Bhubaneshvar-1

Vengurla 36/3

West Bengal

Jhargram-1

T No. 16 of Bapatla

Madhya Pradesh

T No. 40

Vengurla 4

Mid Red x Vetore-56

Forty to sixty day old seedlings are used as rootstocks. Two
pairs of leaves are retained and the seedlings are decapitated at the soft-wood
apical region. Wedge-grafting is then carried out with a 4-5 cm cleft on the
rootstock and with a small portion of the inner surface removed to facilitate a
perfect union of the wedge-shaped scion, which has been prepared by shaving a
portion of the bark and tissue on either side. The union is then secured by
tying with a 15-30 cm polythene strip. The top of the scion is covered with a
polythene cap to protect the apical portion of the scion from desiccation. The
grafted plants are maintained in a lath or screen house for 8-10 days until
sprouts emerge, and then the grafted plants are provided more sunlight and the
caps removed. This wedge grafting technique is carried out by using only the
soft-wood tissues of the stock and scion. The following management techniques
are important in nursing young grafted plants.

- Grafts need to be watered frequently depending
on the season.

- Excess water needs to be drained by providing drainage holes
in polybags.

- Shoots on the rootstocks have to be nipped off
frequently.

- Polythene wrapping at the union has to be removed about
three months after grafting to prevent girdling.

- When the scion leaves turn from brown to green, rootstock
leaves have to be removed (approximately 60 days after grafting).

-Flower shoots that sprout during the normal flowering season should
be removed at the nursery stage.

- To prevent roots penetrating into the ground, grafted plants should be
shifted frequently or placed on thick gauge black polythene sheets.

- Partial shade has to be provided to avoid sun-scorch by
placing the grafted plants in a lath/screen house. Direct sunlight should be
avoided as polythene bags tend to perish. Watering on alternate days should be
done in summer.

- Regular insecticide sprays need to be given to control leaf
sucking insects.

- When transporting grafted plants, terminal shoots and
taproots should be protected.

4. ESTABLISHMENT OF CASHEW ORCHARDS

Large extents of land are available in Karnataka, Maharashtra
and west Bengal for establishing new plantations under the cashew expansion
program. There is also the possibility of expanding cashew cultivation into
non-traditional areas in Madhya Pradesh, Bihar etc.

4.1 Selection of Site and Land Development

When selecting land for cashew, soils with salinity/alkalinity
or waterlogging should be avoided. Soil depth, slope, course texture, soil
fertility and water availability seem to impose very little limitations as
cashew is a hardy crop. For establishing new plantations, land preparation
should begin with the first pre-monsoon rains. Land should be cleared of shrub
vegetation before digging pits for planting.

4.2 Planting Season

Planting of grafted plants is usually carried out during the
monsoon season from July-August both in the west coast as well as in the east
coast. Orchards should have pits dug to receive grafted plants well in advance
of the main monsoon weather.

4.3 Spacing and Planting Systems

A spacing of 7.5m x 7.5m or 8m x 8m is recommended for cashew
which gives a tree density of 175 and 156 trees per ha, respectively. High
density planting at 4m x 4m giving a tree density of 625 trees per ha in the
initial years and subsequently thinning in stages to reach a final spacing of 8m
x 8m is also practiced in some areas. This enables higher returns during the
initial years and as the canopies grow in volume, alternate trees are removed to
achieve the desired final spacing. In level sites however, it would be
advantageous to plant cashew at a spacing of 10m x 5m which will give a tree
density of 200 trees per ha and at the same time providing sufficient space for
growers to plant inter-crops during the initial years of
establishment.

4.4 Planting of Cashew

Pits are usually dug at the onset of the pre-monsoon rains to
a size of 60cm x 60cm x 60cm in light to medium soils. If a hard substrate like
laterite is present pits may be 1m x 1m to compensate for the lesser depth of
soil. It is preferable to dig pits 15-20 days before planting to expose planting
holes to direct sunlight which can help remove termites and other harmful
insects that can damage young plants, if present. When filling, top soil mixed
with compost (5 kg) or poultry manure (2 kg) and 200g of rock phosphate are
placed in the pits. Contour planting is usually followed in sloping areas.
Standard conservation measures need to be followed on steep lands when
establishing cashew plantations.

Young plants are planted in the months of July-August. Most
nurseries supply 5-12 month old grafted plants in polybags. At planting, the
polythene bag is removed without disturbing the ball of earth and the roots.
Care is taken to place the grafted plant in the pits leaving the graft joint at
least 5 cm above ground level. Normally the scion is staked to avoid damage from
wind and the support should remain up to the third year from planting. Most
orchard growers use a mulch around the planting hole to suppress weeds and
conserve moisture.

5. MANAGEMENT AND AFTERCARE OF CASHEW
ORCHARDS

5.1 Terracing and Bunding

In the western and eastern coastal areas cashew is grown
mostly on sloping land. A considerable amount of nutrient leaching and soil
erosion are common in such situations. Growers have been advised to construct
terraces and contour pits to conserve runoff water. Studies on the extent of
root distribution revealed that 90 percent of the root system was confined to a
radius of 2m and a depth of 1 m. In order to achieve maximum utilization of
applied nutrients, fertilizer practices were confined to this part of the root
zone. Before the advent of the south west monsoon in May-June, basins of about
1.5m radius are prepared for 2 year-old trees and subsequently widened to 2m in
the third year. Terraces are made by removing the soil from the elevated portion
above the tree trunks to create basins of 1.5-2m. Contour drains are also
constructed to collect rain water above the tree-line and prevent soil wash from
the slopes.

5.2 Application of Manures and Fertilizer

Application of 10-15 kg of farmyard manure or compost annually
is generally recommended for cashew. In addition, the current fertilizer
recommendation is 500g N (1.1 kg urea), 125g P 2O 5(625g
rock phosphate) and 125g K 2 O (208g muriate of potash) per tree per
year. This has increased production in the All India cashew trials carried out
at the research centers. These trials also showed that the cashew responds well
to increased N applications up to 750g. Since local NPK fertilizer mixtures do
not deliver the required nutrients, application of straight fertilizer is
recommended.

Fertilizer is applied annually at the end of the rainy season
into a shallow trench at the drip line of trees. It is also recommended that
fertilizer be applied in split doses during pre-monsoon (May-June) and
post-monsoon (September-October) periods to assure better uptake of nutrients.
If a single application is done, the post-monsoon period is more suitable when
ground moisture is adequate. One third the recommended dose is applied in the
first year, two third the dose in the second year and the full dose thereafter
(Table 3).

Table 3. Recommended Doses of NPK Fertilizer for Cashew
(g/plant)

Year

Urea (gm)

Rock Phosphate (gm)

Muriate of Potash

1

330

200

70

2

660

400

140

3 onwards

1,100

625

208

Based on the results of research conducted by the National
Coordinated trials, the following methods of fertilizer application are
recommended to cashew growers. In the red loamy soils in low rainfall areas such
as the east coast, fertilizers have to be applied and raked into the soil along
the drip line of tree canopies. In laterite soils and steep lands of the west
coast, fertilizer is applied in circular trenches of about 25 cm width along the
drip line of trees. Trenches are filled and a mulch is applied to ensure soil
moisture retention.

5.3 Weeding

Until tree canopies shade out the weeds, weeding is essential
around the tree trunks up to a radius of about 2 m. The rest of the orchard
requires slashing of under growth at least twice a year. The weeding cycles are
generally confined to the pre-monsoon and post-monsoon periods to coincide with
the fertilizer application.

Alternatively, weedicides may also be applied after slashing,
well in advance of the rainy season if the under growth is too dense. The
recommendation is to apply Agrodar-96 (2-4 D) at the rate of 4 ml/litre of water
followed by Grammoxone at the rate of 5ml/litre of water. Approximately 400
litres of spray is required to cover one ha. The spraying is repeated in the
post monsoon season if the weed load is heavy.

5.4 Mulching

In low rainfall areas, mulching around the base of trees helps
in the control of weeds, retention of moisture and modulation of soil
temperature, especially in the hot summer months. This becomes an essential
operation as cashew is usually planted in very dry areas where other crops are
seldom grown. Most growers utilize the slashed weeds to mulch their
orchards.

5.5 Training and Pruning

During the initial phase of orchard establishment, shoots
arising on the rootstock have to be regularly removed to promote better scion
growth, particularly in the first year after planting when scion rejection could
occur if rootstock shoots are left unchecked. Training of young trees during the
first three years is essential to develop uniform canopies. Training in the
juvenile phase comprises of removing basal branches and water shoots. The plants
are trained to a single stem and branches are allowed to grow about 0.75-1m from
ground level. Deformed branches are also removed during the first few years.
Since cashew trees tend to spread their canopies and lodge easily, proper
staking is also essential. Trees are kept under check by topping off the main
stem at a height of 4-5m from ground level. Orchard operations such as
terracing, weeding, fertilizer application, nut collection and stem/root borer
infestation control can be easily achieved if trees are properly trained.
Pruning should be carried out in August-September at least once in three years
when unwanted growth is removed to provide adequate sunlight into the canopy.
Since fruiting is only encouraged from the third year, de-blossoming has to be
carried out as flower clusters appear during the juvenile phase.

5.6 Plant Protection

Root and stem borer infestation is usually controlled with
swabbing tree trunks with carbaryl (2 %) or using a coal tar/kerosene suspension
(1:2). After pruning of trees, a standard practice is to smear all cut surfaces
with Bordeaux mixture paste (10 %) to prevent fungal infections and die-back. A
1 % Bordeaux spray is also administered if the cut surfaces are small.

More than 60 species of insect pests have been identified in
cashew in India. The major pests are the tea mosquito, stem/root borer, leaf
minor, leaf and blossom webber and flower thrips. No major diseases that cause
economic losses have been reported so far in cashew.

For efficient management of the tea mosquito bug
(Helopeltis antonii), it is important to check the build up of the pest
population on the cashew crop as well as on the alternate hosts such as neem,
drumstick, cocoa, guava etc. Tea mosquito bugs can be effectively controlled by
three sprays at flushing, flowering and fruiting stages with endosulfan or
monocrotophos (0.05 %) for the first and second sprays and carbaryl (0.15 %) for
the third spray. In case of severe infestation, it may sometimes lead to
die-back caused by a secondary infection of Botrydiplodia theobromae. In
such instances it will require pruning of the diseased shoots and swabbing of
the cut surfaces with 10 % Bordeaux paste and spraying the trees with a 1 %
solution of Bordeaux mixture.

The stem and root borer (Plocaecderus ferrugineus L.),
is capable of killing cashew trees. In severe cases of injury by this pest,
gummosis of the stem and yellowing followed by drying of leaves can occur. The
effective control measure is to remove immature stages of the pest and swabbing
the trunk and exposed roots with carbaryl (0.2 %) or neem oil (5 %) and
application of Sevidol 8G (75g/tree) into the basin around the tree.
Prophylactic treatment of swabbing the trunk up to one meter height with coal
tar and kerosene in the ratio of 1:2 twice a year during March and November
could also give effective control. The spray schedule indicated for tea mosquito
bug will also be effective against the control of other foliage and
inflorescence pests.

5.7 Cover-Cropping and Inter-Cropping

Popular cover crops for cashew plantations are Peuraria
javanica, Calapagonium muconoides and Centrosema pubescens which
improve the fertility and moisture balance and help conserve orchard soils.
Cover crop seeds are generally sown with the advent of the monsoons at a seed
rate of about 7 kg/ha. On degraded steep lands, cover crops are usually
established on seed beds between tree rows.

Inter-cropping has become popular with the systematic
establishment of large-scale orchards. It is practiced in the first few years
when there is sufficient space between crop rows with the main objective of
deriving some income until the cashew starts giving economic returns. In Andhra
Pradesh, popular inter-crops are horsegram, cowpea, groundnut etc. Casuarina is
also a tree inter-crop planted at a spacing of 1.5m x 1.5m in cashew orchards in
Andhra Pradesh and Orissa. In the west Godavari district of Andhra Pradesh,
cashew is grown in combination with casuarina and coconut.

In Kerala and coastal Karnataka, pineapple is grown as a
biennial crop in the initial 4-5 years and farmers find it far more profitable
than crops such as redgram and cassava. Adopting a two-row system of planting in
contour trenches, yields of 15-20 tons/ha have been achieved from this
inter-crop. The pineapple inter-crop also indirectly benefits the main cashew
crop as contour trenches help to conserve water and nutrients. When hedge-row
planting at a spacing of 5m x 10m is used, inter-crops of Acacia, casuarina etc.
are taken without any ill-effects on the main crop. These trees are planted
about 3.5 m away from the cashew in two-row plots spaced 1m x 1m apart in the
center of crop avenues.

5.8 Irrigation and Drainage

Cashew cultivation is generally carried out under rainfed
conditions. In homesteads however, it is preferable to give some supplementary
irrigation during the warm summer months from January to March. An application
of about 200 liters of water per tree every fortnight was found to double cashew
yields in trials conducted at the National Research Center at Puttur. In the
sandy tracts of the East coast, although frequency and quantity of water applied
varies, trees are watered during the summer months. Both in the homesteads and
large-scale orchards, cashew is susceptible to waterlogging and proper drainage
is essential in low lying areas.

6. HARVESTING OF NUTS AND CASHEW YIELDS

Bearing commences after the third year of planting and the
trees will be in full production by the tenth year whilst the economic life of a
tree is about 20 years. The main harvesting season is from February to May. Most
farmers harvest their crop before they drop to prevent pilferage. This very
often results in poor quality of the kernels. The optimum stage of harvest is
when nuts drop to the ground. High quality nuts are obtained when freshly fallen
nuts are separated from the cashew apples and sun dried for 2-3 days to bring
down the moisture percentage from about 25 percent to below 9 percent. It is
very essential to dry the nuts in order to prevent spoilage during storage. The
drying process helps to retain flavor and quality of the kernels. When cashew
apples are used for processing, harvesting has to be carried out before they
drop. A simple test of maturity is to float nuts in water when mature nuts will
sink while the immature and unfilled nuts will float. Nuts are usually gathered
every week during the harvest season. Cashew apples for the fresh fruit market
should be harvested daily.

Normally, about 92 % of the trees yield by the third year from
planting. The average yield per tree increases from about 2 kg at 3-5 years to 4
kg at 6-10 years and 5-10 kg when trees are 11-15 years of age. Thereafter,
trees yield in excess of 10 kg as the trees get older.

7. MARKETING

Raw cashew nuts are a seasonal commodity and the trading
season is from March to May. Growers usually supply the primary or village
markets where small traders collect and supply the urban markets. The cashew
trade is seldom handled by exclusive traders. Usually, those traders who collect
other plantation products also trade in cashew. Due to the highly competitive
nature of the cashew trade growers have few marketing problems. When large
quantities are collected by middlemen, the processors enter the marketing chain
and make wholesale purchases. Grades and standards for cashew are yet to be
introduced in India. Quality is generally determined by appearance and cutting
tests that traders employ prior to purchase. The raw cashew nut market involves
a large amount of capital where nearly 80 percent of the produce is transacted
within a matter of 35 days. The current value of Indian production is estimated
at around Rs. 10,000 million. This capital is made available by industry for
procurement and processing operations.

There are no growers cooperatives or organizations for
cashew marketing. In Kerala however, the government has been involved in the
procurement process and supply to large-scale processors. This adversely
affected the cashew trade and has now been replaced by a free market
policy.

In addition to the local production of nearly 430,000 tons,
India also imports a considerable quantity of raw nuts from several African and
South-east Asian countries to satisfy the national processing capacity of
700,000 tons established in the country.

8. POTENTIAL FOR CASHEW NUT PRODUCTION
DEVELOPMENT

In 1960-61, 228,000 tons of raw nuts were processed of which
nearly 50 percent was imported. During the same year, 44,000 tons of processed
kernels were exported which accounted for 77 percent of the total kernel output
from the industry. The processing output has considerably increased in recent
years and in 1995-96, about 640,000 tons were processed (Table 4) of which 65
percent raw nuts were obtained from local production. Domestic consumption has
also increased considerably from 13,000 tons in 1960-61 to 92,000 tons in
1995-96, while the country also earned a foreign exchange equivalent of Rs.
12,320 million (US$ 352 million) through the export of cashew kernels and cashew
nut shell liquid (CNSL). Export earnings reached a peak in 1994-95 when 77,000
tons of kernels were exported with a value of Rs. 12,440 million (US$ 355
million). With the establishment of new orchards using high yielding
vegetatively propagated planting material, the future looks bright for the
cashew industry in India.

A study of the industry prior to 1985 revealed that most of
the plantations were of seedling origin and cashew cultivation was mainly
carried out as an afforestation and conservation program for waste lands rather
than an economic venture. Since productivity was not the basic objective of such
a program, the cashew was maintained under highly neglected conditions. Poor
soil fertility in cashew growing areas, seedling progenies of nondescript origin
and neglect of the crop resulted in low productivity. This was prevalent in most
of the cashew growing areas of Karnataka, Goa, Andhra Pradesh, Orissa and Tamil
Nadu. Neglected trees established for conservation purposes hardly responded to
the application of any inputs. Seedling progenies that were established in
Maharashtra however, showed that these plantations responded to the application
of modern inputs developed by research. These seedling progenies were from
selected stock and orchards had received better attention from the beginning of
their establishment. In order to ensure better productivity, all new plantings
are encouraged to use vegetatively propagated material of recommended cultivars
and the use of seedlings is completely discouraged.

One of the major thrusts being advocated at present is to
rehabilitate existing unthrifty seedling plantations. It may however, not be
profitable to attempt rehabilitation of senile and sparsely populated orchards.
The working group responsible for the preparation of the 8th national
plan revised yield estimates from 2 tons per ha to one ton per ha, mainly having
these plantations in view. The current area of 635,000 ha is likely to reach 1
million ha by the turn of the century. Cashew is being considered as a candidate
crop for rehabilitation of waste lands by many development planners. The issue
is however, being debated whether more waste land be brought under cashew or
rehabilitation of old orchards be undertaken using elite planting material.
Waste lands that are now being considered are far more inferior to those areas
which already have cashew plantations. The cashew crop has contributed in some
ways to conserving the soil in the existing orchards. The logical alternative
would therefore be, to utilize existing cashew lands for a development program
using available technologies to reach the required production levels without
expanding into any more degraded waste lands.

10. CONCLUDING REMARKS

One of the key factors in favor of expanding the cashew
industry in India is the stable price in the International market when compared
to other nuts such as almond, hazel nut etc. Nutritionally, cashew also compares
well with other tree nut crops. It is a commodity rich in unsaturated fatty
acids with high protein and low levels of saturated fats and soluble sugars.
Higher levels of polyunsaturated fatty acids which lower blood cholesterol is
particularly of high nutritional significance. The crop is steadily gaining
acceptance in many western markets where consumers are more health
conscious.

The elaborate research network and development infrastructure
in India is beneficial for the expansion of the cashew industry. Development and
introduction of eco-friendly production packages such as organic farming and
integrated pest management can provide a further boost to the development of the
crop and the cashew industry in the future.